Questions[scope](server)

What is the difference between "Preferred Life Time" and "Valid Life Time" lease. What is the point of preferred and why not just use valid life time lease? Thanks.

As I was running through the scope wizard in DHCP for Windows Server 2008 R2, the wording on the wizard was slightly confusing: it seems to imply that changes I make to the default gateway and DNS servers for this new scope will be applied for ALL scopes. That doesn't really make sense, but I wanted to ask to be sure: can the new scope wizard mess up other scopes or global DHCP settings?

I'm running Windows Server 2008 R2 for my DHCP server. We are about to switch over to a VoIP system and Cisco VoIP phones. I would like to assign a specific range of IPs to these phones which will have a common MAC prefix (ex. 00:01:02). I would prefer to have them in the same scope as our computers if possible. Does anyone have any suggestions?

I have a problem in one of my shell scripts. Asked a few colleagues, but they all just shake their heads (after some scratching), so I've come here for an answer.

According to my understanding the following shell script should print "Count is 5" as the last line. Except it doesn't. It prints "Count is 0". If the "while read" is replaced with any other kind of loop, it works just fine. Here's the script:

echo "1">input.data
echo "2">>input.data
echo "3">>input.data
echo "4">>input.data
echo "5">>input.data

CNT=0 

cat input.data | while read ;
do
  let CNT++;
  echo "Counting to $CNT"
done 
echo "Count is $CNT"

Why does this happen and how can I prevent it? I've tried this in Debian Lenny and Squeeze, same result (i.e. bash 3.2.39 and bash 4.1.5. I fully admit to not being a shell script wizard, so any pointers would be appreciated.

I want to implement a redundancy solution. I have two subnets all windows XP machines - each with their own DHCP server - joined by a bridge.

Currently - all machines get DHCP leases from the one DHCP server with the other disabled.

For when the bridge goes down - I want to split my DHCP scope among multiple servers. How can I do this on Windows XP client machines?